<!doctype HTML>
<style>
::-webkit-scrollbar {
    display: none;
}
</style>
<div style="column-count: 2; width: 800px; height: 300px;">
  First column. Green should show on scroll.
  <div id="scroller" style="width: 400px; height: 250px;  overflow-y: auto;">
    <div style="width: 300px; height: 300px; background: green"></div>
  </div>
  Second column.
</div>
